• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.977-981
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• 1996

A load sensing hydraulic system is widely used to military and commercial mobile applications fur its high running efficiency. Although concept and general control schemes are well known, the poor maneuverability of simultaneous multioperation of actuators still remains to be solved. In this paper, a new control algorithm is proposed to prevent the saturation of the system in such operating conditions, in which the total required flowrate of actuators may exceed the pump supply flowrate. The effectiveness of the proposed algorithm is verified through experiments.

• Journal of the Korea Safety Management & Science
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• v.13 no.2
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• pp.211-217
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• 2011

The government has been operating the long-term care insurance since 2008. In June 2010, the government manual wheelchairs, electric beds, manual beds, mattresses prevent pressure ulcers, mobile tub, bath lifts, including six items were changed to rental-only item. For the successful settlement of welfare equipment rental system, The efforts to prevent inconvenience of welfare equipment user's and improvement of the system for the activation is needed. The main object of this study is to identify the factors affecting satisfaction of welfare equipment rental and seek to proposals of revitalizing equipment rental system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.7
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• pp.531-542
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• 2002

Transcritical$CO_2$ systems are under consideration for use as residential/mobile air conditioners. In these systems, an internal heat exchanger is usually adopted to improve both capacity and/or COP of the $CO_2$ system in lower operating pressure range of gas cooler. A program has been developed to analyse the performance of internal heat exchangers using the section-by-section method. The internal heat exchanger of coaxial configuration is first analyzed and fairly good agreements with the data are obtained, And then the internal heat exchanger of multiple circular coil configuration has been investigated. The results obtained from the parametric study provide the guidelines for the initial design and manufacturing concepts of the internal heat exchanger in transcritical $CO_2$ system. Further studies are necessary to develop the heat transfer correlations of carbon dioxide in the tubes to obtain more accurate results.

• Journal of Digital Convergence
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• v.11 no.2
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• pp.257-262
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• 2013

In mobile market which has been developed drastically, short distance mobile Near Field Communication is becoming the conversation topic. Google adopted this NFC technology to Android 플랫폼 for securing the leadership and many another countries including domestic companies are putting spurs to develop service and technology by connecting mobile carrier and the financial. Within this circumstance, most noticeable issue is securing stability of nfc application service. Android 플랫폼 is operating system of mobile device and also a software stack which is required limited hardware and immediate response. However, since its structural characteristic which is suitable for limited hardware, the response is not quite stable for real time process. That is, this paper researches by analyzing real time response of NFC related library provided from Android 플랫폼 and applying the result to NFC application for securing stable data process and response.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.429-432
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• 2012

Mobile devices diffusion begins by the iPhone and spreads by the Android. A widely used mobile devices is Smartphone(iPhone, Android, Bada, WindowPhone7, BlackBerry, etc) and Tablet(iPad, Android). In the past, we have developed a dedicated application for device. But, Now we must develop a application by considering the characteristics of the operating system. Accordingly, many problems occurred and other developmet methods have emerged. In this paper, we learn about MobileHybridApp development tool-oriented One Source Multi Use-and compare the differences, propose a method to develop context-sensitive.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.1
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• pp.415-439
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• 2014

The purpose of this study is to analyze mobile web accessibility of public libraries. To achieve this, accessibility checklists were driven from mobile web and application guidelines. The study also conducted automatic and manual evaluations. As results, the study found that text alternatives for resource image, main menu, image for text contents were mainly missing. In addition, focus for retrieval, operating system accessibility for retrieval, and id & password label, color difference for library calendar and seat reservation, brightness difference for main manu and resource display, and space between controls for retrieval were mainly missing. The study also suggested focal missing areas for main library services. It will be utilized as checklists for development of mobile services.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1288-1296
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• 2012

A candidate hybrid satellite and terrestrial network architecture, MSS/ATC(Mobile Satellite Service/Ancillary Terrestrial Component), is proposed for utilizing efficiently the exist MSS bands. Studies on the adjacent channel interference from the existing terrestrial mobile services and MSS/ATC itself are important to allocate a new ATC service frequency in MSS band. In this paper, we have analyzed the minimum permission power of terrestrial base station and the capacity loss with parameters of ACIR, number of MS(mobile Station) and MES(Mobile Earth Station) in uplink, and also, the capacity performance based on 1 beam and 1 cell assumption for MSS/ATC in downlink. The ACIR requirements are estimated in two MSS/ATC frequency allocation scenarios for 5 MHz and 10 MHz guard band to share spectrum with adjacent systems, and according to these ACIR requirements the service coverage and the receiver filter for ATC system should be designed in near future.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.227-235
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• 2014

Mobile virtualization is an approach to mobile device management in which two virtual platforms are installed on a single wireless device. A smartphone, a single wireless device, might have one virtual environment for business use and one for personal use. Mobile virtualization might also allow one device to run two different operating systems, allowing the same phone to run both RTOS and Android apps. In this paper, we propose the techniques to virtualize the cores of a multicore, allowing the reassign any number of vCPUs that are exposed to a OS to any subset of the pCPUs. And then we also propose the real-time scheduling method to assigning the vCPUs to the pCPU. Suggested technology in this paper solves problem that increases time of real-time process when interrupt are handled, and is able more to fast processing than previous algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1524-1530
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• 2016

Recently, research about an electronic attendance-absence recording system has been actively carried out using smart devices. Using an electronic attendance-absence recording system, professors can check their students' attendance on a real-time basis and manage their attendance records. In this paper, we proposed a real-time electronic attendance-absence recording system using face detection and face recognition based on web application. It can solve the spatial, temporal, cost issues belong to electronic attendance-absence recording system using AIDC(Automatic Identification and Data Capture). A proposed system is running on web server and made by HTML5(Hyper Text Markup Language ver.5). So professor connect to server using mobile web browser on mobile device and real-time manage electronic attendance-absence recording with real-time send or receive image data. In addition, the proposed system has an advantage capable of installation and operation, regardless of the operating system because it operates based on the Python flask framework.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.19-24
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• 1998

The main goal of this paper is to propose and to test a radio protocol based CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) for the purpose of enhancing the existing medical information system. The feature of the new medical information system, Medical Application Radio System(MARS), which operating in real time is the transmission of medical information in bi-direction between the hospital control office and patients mobile stations. MARS monitors patients linked to the network by radio and provides quick alarm, flexible documentation capabilities, asnd fast treatment for the analysis of collected medical data. The existing medical information system, radio telemetry system which transfers the message of patients to the CAP(Central Access Point) unit in one way at the speed of 9.6Kbps and operates a channel frequency bandwidth. To verify the Performance of the proposed system, we have performed the numerical analysis and have implemented a test system which consists of the 2.4Ghz radio transceiver and personal computer.